[Dovecot] imaptest10 and stalled messages

[Mike Brudenell]

Greetings -

I've now got as far as playing with the imaptest10 test utility to  
see if I can stress-test our development server.  imaptest10 is built  
against dovecot-1.0rc28

It may just be that I'm excessively heavy handed, but when I let  
imaptest10 rip with the command...

./imaptest10 user=test%03d host=testserver.imap.york.ac.uk clients=50  
mbox=./dovecot.mbox msgs=1000 secs=30 logout=10

...after 15 seconds or so I started getting output along the lines of:

Logi List Stat Sele Fetc Fet2 Stor Dele Expu Appe Logo
100%  50%  50% 100% 100% 100%  50% 100% 100% 100%  10%
                           30%                  5%
    2    0    1    1    1    0    0    0    0    0    0  50/ 50
    2    0    0    1    1    0    0    0    0    0    0  50/ 50
    0    0    2    2    0    1    1    1    1    1    0  50/ 50
    2    0    2    2    0    1    1    1    1    1    2  50/ 50
    0    0    1    1    0    0    0    0    0    0    0  50/ 50
- 16. stalled for 16 secs in LOGIN
- 17. stalled for 16 secs in LOGIN
- 18. stalled for 16 secs in LOGIN
    2    1    1    2    1    0    0    0    0    0    0  50/ 50
- 17. stalled for 17 secs in LOGIN
- 18. stalled for 17 secs in LOGIN
- 22. stalled for 16 secs in LOGIN
- 23. stalled for 16 secs in LOGIN
- 24. stalled for 16 secs in LOGIN
    1    0    1    1    0    0    0    0    0    0    0  50/ 50
- 17. stalled for 18 secs in LOGIN
- 18. stalled for 18 secs in LOGIN
- 22. stalled for 17 secs in LOGIN
- 23. stalled for 17 secs in LOGIN
- 24. stalled for 17 secs in LOGIN
- 28. stalled for 16 secs in LOGIN
- 29. stalled for 16 secs in LOGIN
- 30. stalled for 16 secs in LOGIN
- 31. stalled for 16 secs in LOGIN
- 32. stalled for 16 secs in LOGIN

The "stalled" log lines continue until the test completes.  I'm  
assuming it's just that I'm pushing our hardware beyond its  
reasonable limits: it is only an oldish development box...

     Sun v120 with 1 650MHz SPARC processor and 1Gbyte RAM

Dovecot is using shadow password file authentication. The mail  
folders are in Maildirs, NFS-mounted from a NetApp filer, and each  
account's INBOX has around 1000 messages in it.  Control and Index  
files are on local disk.

By the end of the 30 second test run load average has climbed to  
around 11

I don't know how "active" the imaptest10 utility is when it's  
running, but do you think I should be concerned by the "stalled"  
messages?  That is, do you think I have something configured amiss?   
Or is it likely just to be I'm expecting too much of our hardware?   
(The real system will have beefier Suns with Opteron-based CPUs, more  
memory, etc)

With thanks,
Mike B-)

PS.  I forgot to say: despite all this activity there's not a single  
error logged by Dovecot in the (admittedly short at this stage) test  
runs.

-- 
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